bisecting fixing commit since c10b57a567e4333b9fdf60b5ec36de9859263ca2
building syzkaller on 435c6d538899a51dde5bbc2472cd4e7ecb2ef270
testing commit c10b57a567e4333b9fdf60b5ec36de9859263ca2 with gcc (GCC) 8.1.0
kernel signature: 066e64dcf93a0b69905515cf2d7b61ac22e64ab1dadfcd890d8091f379724ef1
all runs: crashed: KASAN: global-out-of-bounds Read in nfnetlink_parse_nat_setup
testing current HEAD ab9dfda232481dcfaf549ce774004d116fc80c13
testing commit ab9dfda232481dcfaf549ce774004d116fc80c13 with gcc (GCC) 8.1.0
kernel signature: 3d1b07ddd2e75111a27e778243eab198b19de54594b430a01763f71d4d2bc88d
all runs: crashed: KASAN: global-out-of-bounds Read in nfnetlink_parse_nat_setup
revisions tested: 2, total time: 26m26.394005009s (build: 18m51.362553713s, test: 6m7.273324652s)
the crash still happens on HEAD
commit msg: Linux 4.14.180
crash: KASAN: global-out-of-bounds Read in nfnetlink_parse_nat_setup
IPv6: ADDRCONF(NETDEV_UP): veth1_virt_wifi: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_virt_wifi: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready
IPv6: ADDRCONF(NETDEV_UP): veth1_vlan: link is not ready
==================================================================
BUG: KASAN: global-out-of-bounds in nfnetlink_parse_nat net/netfilter/nf_nat_core.c:747 [inline]
BUG: KASAN: global-out-of-bounds in nfnetlink_parse_nat_setup+0x30e/0x320 net/netfilter/nf_nat_core.c:784
Read of size 8 at addr ffffffff875b9b78 by task syz-executor.2/7750
device veth0_vlan entered promiscuous mode

CPU: 0 PID: 7750 Comm: syz-executor.2 Not tainted 4.14.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xf7/0x13b lib/dump_stack.c:58
 print_address_description.cold.7+0x135/0x1c9 mm/kasan/report.c:252
device veth1_vlan entered promiscuous mode
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report.cold.8+0x11a/0x2d3 mm/kasan/report.c:409
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 nfnetlink_parse_nat net/netfilter/nf_nat_core.c:747 [inline]
 nfnetlink_parse_nat_setup+0x30e/0x320 net/netfilter/nf_nat_core.c:784
IPv6: ADDRCONF(NETDEV_UP): macvlan0: link is not ready
 ctnetlink_parse_nat_setup+0x61/0x3d0 net/netfilter/nf_conntrack_netlink.c:1421
IPv6: ADDRCONF(NETDEV_UP): macvlan1: link is not ready
 ctnetlink_setup_nat net/netfilter/nf_conntrack_netlink.c:1491 [inline]
 ctnetlink_create_conntrack+0x366/0xf10 net/netfilter/nf_conntrack_netlink.c:1840
 ctnetlink_new_conntrack+0x432/0xd30 net/netfilter/nf_conntrack_netlink.c:1964
 nfnetlink_rcv_msg+0x89a/0xa70 net/netfilter/nfnetlink.c:214
 netlink_rcv_skb+0x133/0x370 net/netlink/af_netlink.c:2433
 nfnetlink_rcv+0x176/0x1570 net/netfilter/nfnetlink.c:515
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x40b/0x600 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x730/0xbd0 net/netlink/af_netlink.c:1878
IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready
IPv6: ADDRCONF(NETDEV_UP): veth1_macvtap: link is not ready
device veth0_macvtap entered promiscuous mode
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0xf0 net/socket.c:656
 ___sys_sendmsg+0x625/0x920 net/socket.c:2062
IPv6: ADDRCONF(NETDEV_UP): macvtap0: link is not ready
 __sys_sendmsg+0xc1/0x140 net/socket.c:2096
device veth1_macvtap entered promiscuous mode
IPv6: ADDRCONF(NETDEV_UP): macsec0: link is not ready
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0xd/0x20 net/socket.c:2103
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c889
RSP: 002b:00007f28ed307c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f28ed3086d4 RCX: 000000000045c889
RDX: 0000000000000000 RSI: 0000000020000640 RDI: 0000000000000003
RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
IPv6: ADDRCONF(NETDEV_UP): veth0_to_batadv: link is not ready
R13: 000000000000095e R14: 00000000004cc163 R15: 000000000076bf0c
IPv6: ADDRCONF(NETDEV_UP): veth1_to_batadv: link is not ready

batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
The buggy address belongs to the variable:
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
 nft_nat_ops+0xb8/0xc0

Memory state around the buggy address:
 ffffffff875b9a00: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff875b9a80: 00 00 fa fa fa fa fa fa 00 00 00 00 00 00 00 00
>ffffffff875b9b00: 00 00 00 fa fa fa fa fa 04 fa fa fa fa fa fa fa
                                                                ^
 ffffffff875b9b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff875b9c00: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================